Features to improve and sense tympanic membrane apposition by tympanostomy tube delivery instrument

ABSTRACT

A tympanostomy tube delivery device comprises a shaft assembly, a pressure equalization tube, and a sensor. The shaft assembly comprises a cannula and a pusher operable to translate relative to the cannula. The pressure equalization tube is positioned within the shaft assembly. The pusher is operable to drive the pressure equalization tube out of the shaft assembly. The sensor is operable to detect a physical parameter associated with engagement between the distal end of the shaft assembly and a tympanic membrane. A controller may activate a feedback device to inform an operator that the distal end of the shaft assembly has achieved suitable apposition with the tympanic membrane, based on information from the sensor.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/804,553, entitled, “Features to Improve and Sense Tympanic MembraneApposition by Tympanostomy Tube Delivery Instrument,” filed Mar. 14,2013, the disclosure of which is hereby incorporated by reference hereinin its entirety.

BACKGROUND

Some children may exhibit recurrent episodes of otitis media and/or-otitis media with effusion. Treatment of severe cases may involve theplacement of a pressure equalization tube or tympanostomy tube throughthe tympanic membrane to provide adequate drainage of the middle ear byproviding fluid communication between the middle and outer ear. Inparticular, such a tube may provide a vent path that promotes drainageof fluid from the middle ear via the Eustachian tube and may thus reducestress imposed on the tympanic membrane from pressure within the middleear. This may further reduce the likelihood of future infections andpressure induced ruptures of the tympanic membrane. Pressureequalization tubes may fall out spontaneously within about a year ofplacement. Exemplary pressure equalization tube delivery systems aredisclosed in U.S. Pat. No. 8,052,693, entitled “System and Method forthe Simultaneous Automated Bilateral Delivery of Pressure EqualizationTubes,” issued Nov. 8, 2011, the disclosure of which is incorporated byreference herein. Additional exemplary pressure equalization tubedelivery systems are disclosed in U.S. Pat. No. 8,249,700, entitled“System and Method for the Simultaneous Bilateral Integrated TympanicDrug Delivery and Guided Treatment of Target Tissues within the Ears,”issued Aug. 21, 2012, the disclosure of which is incorporated byreference herein. Still additional exemplary pressure equalization tubedelivery systems are disclosed in U.S. Pub. No. 2011/0015645, entitled“Tympanic Membrane Pressure Equalization Tube Delivery System,”published Jan. 20, 2011, now U.S. Pat. No. 8,864,774, issued Oct. 21,2014, the disclosure of which is incorporated by reference herein.

Insertion of a pressure equalization tube may be performed using generalanesthesia in some cases, which may require additional resources such asan operating room, the presence of an anesthesiologist, and time in arecovery room. Furthermore, the use of general anesthesia may includecertain risks that a patient may or may not be comfortable withundertaking. Some pressure equalization tube delivery systems andmethods provide a local anesthetic through iontophoresis. Examples ofsuch systems and methods are disclosed in U.S. Pub. No. 2010/0198135,entitled “Systems and Methods for Anesthetizing Ear Tissue,” publishedAug. 5, 2010, now U.S. Pat. No. 8,840,602, issued Sep. 23, 2014, thedisclosure of which is incorporated by reference herein. Additionalexamples of such systems and methods are disclosed in U.S. Pat. No.8,192,420, entitled “Iontophoresis Methods,” issued Jun. 5, 2012, thedisclosure of which is incorporated by reference herein.

While a variety of pressure equalization tube delivery systems andmethods have been made and used, it is believed that no one prior to theinventor(s) has made or used an invention as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

It is believed the present invention will be better understood from thefollowing description of certain examples taken in conjunction with theaccompanying drawings, in which like reference numerals identify thesame elements and in which:

FIG. 1 depicts a perspective view of an exemplary pressure equalizationtube delivery device (PETDD);

FIG. 2 depicts a perspective view of the PETDD of FIG. 1, with a housinghalf omitted;

FIG. 3 depicts an exploded elevational view of actuation features of thePETDD of FIG. 1;

FIG. 4 depicts a perspective view of the distal end of a dilator of theactuation features of FIG. 3;

FIG. 5 depicts a perspective view of the distal end of a shield tube ofthe actuation features of FIG. 3;

FIG. 6 depicts a perspective view of the distal end of a pusher of theactuation features of FIG. 3;

FIG. 7 depicts a perspective view of the distal end of a piercer of theactuation features of FIG. 3;

FIG. 8 depicts a cross-sectional side view of the actuation features ofFIG. 3 with an exemplary pressure equalization (PE) tube;

FIG. 9 depicts a displacement and operational diagram associated withthe actuation features of FIG. 3;

FIG. 10 depicts an exploded perspective view of a trigger mechanism ofthe actuation features of FIG. 3;

FIG. 11 depicts a perspective view of the proximal side of a pawl of thetrigger mechanism of FIG. 10;

FIG. 12 depicts a perspective view of the distal side of the pawl ofFIG. 11;

FIG. 13 depicts a perspective view of the proximal underside of a buttonactuator of the trigger mechanism of FIG. 10;

FIG. 14 depicts a bottom plan view of the trigger mechanism of FIG. 10,showing the pawl engaged with the camshaft;

FIG. 15A depicts a cross-sectional view of the trigger mechanism of FIG.10, taken along line 15-15 of FIG. 14, showing the pawl engaged with thecamshaft;

FIG. 15B depicts a cross-sectional view of the trigger mechanism of FIG.10, taken along line 15-15 of FIG. 14, showing the pawl disengaged fromthe camshaft, with the button actuator omitted;

FIG. 16A depicts a cross-sectional view of the pawl and button actuatorof FIGS. 11 and 13, taken along line 16-16 of FIG. 15A, showing thebutton actuator arresting the pawl;

FIG. 16B depicts a cross-sectional view of the pawl and button actuatorof FIGS. 11 and 13, taken along line 16-16 of FIG. 15A, showing thebutton actuator translated laterally to enable movement of the pawl;

FIG. 17 depicts a perspective view of the proximal side of an exemplaryPE tube suitable for delivery by the PETDD of FIG. 1;

FIG. 18 depicts a perspective view of the distal side of the PE tube ofFIG. 17;

FIG. 19 depicts a distal elevational view of the PE tube of FIG. 17;

FIG. 20 depicts a side elevational view of the PE tube of FIG. 17,positioned within a tympanic membrane;

FIG. 21 depicts a side elevational view of a PETDD cannula having anexemplary alternative tip member, with the outer tube and tip membershown in cross-section, engaged with a tympanic membrane;

FIG. 22A depicts a side elevational view of a an exemplary alternativePETDD cannula, with the cannula shown in cross-section, engaged with atympanic membrane;

FIG. 22B depicts a side elevational view of the PETDD cannula of FIG.22A, having delivered a PE tube in the tympanic membrane;

FIG. 23 depicts a side elevational view of a PETDD cannula havinganother exemplary alternative tip member;

FIG. 24 depicts a perspective view of an exemplary PETDD cannula with anannular conductor at the distal tip, in combination with a ground padand a controller;

FIG. 25 depicts a perspective view of an exemplary PETDD cannula with aplurality of discrete conductors at the distal tip, in combination witha ground pad and a controller;

FIG. 26 depicts a perspective view of an exemplary PETDD cannula with aplurality of discrete conductor pairs at the distal tip, in combinationwith a controller;

FIG. 27 depicts a perspective view of an exemplary PETDD cannula with anannular conductor at the distal tip, in combination with a controller;

FIG. 28 depicts a perspective view of an exemplary PETDD cannula with aplurality of light pipes terminating at the distal tip; and

FIG. 29 depicts a perspective view of an exemplary PETDD cannula with anintegrated light fiber and imaging device.

FIG. 30 shows a schematic representation of a distal end view of a shaftand an electrode disposed within an inner diameter of the shaft.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the invention may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presentinvention, and together with the description serve to explain theprinciples of the invention; it being understood, however, that thisinvention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc., described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc., that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.,should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

I. Exemplary Pressure Equalization Tube Delivery Instrument

As noted above, a pressure equalization (PE) tube may be delivered tothe tympanic membrane (TM) of a patient as a way of treating, forexample, otitis media. In some instances, a delivery instrument may beused to insert PE tubes in the tympanic membrane (TM) without the use ofgeneral anesthesia. FIG. 1 shows an exemplary equalization tube deliverydevice (PETDD) (100) that may be used in such procedures. It should beunderstood that PETDD (100) may be used with an endoscope to providevisualization of the tympanic membrane (TM) during use of PETDD (100).It should also be understood that a patient may receive local anesthesiaat the tympanic membrane (TM) through a process of iontophoresis beforePETDD (100) is actuated to deploy a PE tube. By way of example only,such iontophoresis may be provided in accordance with at least some ofthe teachings of U.S. Pub. No. 2010/0198135, published Aug. 5, 2010, nowU.S. Pat. No. 8,840,602, issued Sep. 23, 2014, the disclosure of whichis incorporated by reference herein; and/or in accordance with at leastsome of the teachings of U.S. Pat. No. 8,192,420, the disclosure ofwhich is incorporated by reference herein. Other suitable ways in whichPETDD (100) may be used will be apparent to those of ordinary skill inthe art in view of the teachings herein.

As shown in FIG. 1, PETDD (100) of this example comprises a handpiece(102) and a cannula (120) extending distally from handpiece (102).Handpiece (102) is formed by two housing (104) halves that are joinedtogether and that include internal features configured to supportvarious components of PETDD (100) as will be described below. Handpiece(102) is configured to be handheld, such that an operator may fullyoperate PETDD (100) using a single hand. A pushbutton (106) is slideablydisposed in housing (104) and includes exposed portions extendinglaterally from each side of handpiece. Pushbutton (106) is operable tobe pushed along a path that is transverse to handpiece (102) in order toactuate PETDD (100) as will be described in greater detail below. Apull-pin (108) extends distally from handpiece (102) and is configuredto prevent pushbutton (106) from being actuated, thereby preventingPETDD (100) from being actuated, so long as pull-pin (108) is disposedin handpiece (102). Pull-pin (108) is nevertheless removable fromhandpiece (102) to effectively unlock pushbutton (106) and therebyenable actuation of PETDD (100). Cannula (120) of the present examplecomprises an elongate tube having a clear tip member (122) at the distalend of cannula (120). Clear tip member (122) is configured to contact apatient's tympanic membrane (TM) while enabling visualization of thedistal end of cannula (120). In some versions, tip member (122) isformed of a soft or elastomeric material such as rubber, soft plastic,etc. This may dampen vibrations that might otherwise be transmitted fromcannula (120) to the patient's tympanic membrane (TM) during firing ofPETDD (100). In addition or in the alternative, tip member (122) mayinclude some other kind of dampening feature as will be apparent tothose of ordinary skill in the art in view of the teachings herein.

As can be seen in FIG. 2, housing (104) supports a camshaft (130) andvarious other components. Camshaft (130) includes a dilator track (132),a shield tube track (134), a stopper track (137), a pusher track (136),and a piercer track (138). Tracks (132, 134, 136, 137, 138) are formedas recesses in camshaft (130) and each track (132, 134, 136, 137, 138)has a unique configuration in order to provide a particular sequence ofoperation of translating components as will be described in greaterdetail below. A torsion spring (140) is coupled to the proximal end ofcamshaft (130). Torsion spring (140) is also grounded against housing(104). Torsion spring (140) resiliently provides a rotational bias tocamshaft (130). In particular, torsion spring (140) urges camshaft (130)to rotate in the clockwise direction (viewed from the distal end ofPETDD (100) toward the proximal end of PETDD (100)) about thelongitudinal axis of camshaft (130). As will be described in greaterdetail below (200), a trigger mechanism selectively resists suchrotation. While torsion spring (140) is used to bias camshaft (130) inthe present example, it should be understood that any other suitabletypes of components may be used to bias camshaft (130).

As shown in FIG. 3, various components are engaged with camshaft (130)and are thereby actuated by rotation of camshaft (130). In particular, adilator tube (150), a shield tube (160), a pusher tube (170), and apiercer (180) are all engaged with camshaft (130). Tubes (150, 160, 170)and piercer (180) are all coaxially disposed within cannula (120).Piercer (180) is coaxially and slideably disposed within pusher tube(170), which is coaxially and slideably disposed within shield tube(160), which is coaxially and slideably disposed within dilator tube(150), which is coaxially and slideably disposed within cannula (120).Tubes (150, 160, 170) and piercer (180) all translate relative tocannula (120) in a particular sequence in order to deploy a PE tube aswill be described in greater detail below. This sequence is driven byrotation of camshaft (130).

A cam follower (152) is fixedly secured to the proximal end of dilatortube (150). Cam follower (152) includes a laterally projecting pin (154)that is disposed in dilator track (132), such that rotation of camshaft(130) causes cam follower (152) and dilator tube (150) to translate.Similarly, a cam follower (162) is fixedly secured to the proximal endof shield tube (160). Cam follower (162) includes a laterally projectingpin (164) that is disposed in shield tube track (134), such thatrotation of camshaft (130) causes cam follower (162) and shield tube(160) to translate. A cam follower (172) is fixedly secured to theproximal end of pusher tube (170). Cam follower (172) includes alaterally projecting pin (174) that is disposed in pusher tube track(136), such that rotation of camshaft (130) causes cam follower (172)and pusher tube (170) to translate. Finally, a cam follower (182) isfixedly secured to the proximal end of piercer (180). Cam follower (182)includes a laterally projecting pin (184) that is disposed in piercertrack (138), such that rotation of camshaft (130) causes cam follower(182) and piercer (180) to translate. Stopper track (137) is simplyannular in this example and includes a fixed elastomeric plug (135). Aninwardly protruding boss (not shown) of housing (104) is disposed instopper track (137). This boss remains disposed in stopper track (137)during rotation of camshaft (130).

As shown in FIG. 4, the distal end of dilator tube (150) includes aplurality of generally flexible leaves (156) that are separated bylongitudinally extending gaps (158). Leaves (156) are resiliently biasedto assume the inwardly deflected positioning shown in FIG. 4; but areoperable to flex outwardly from this positioning as will be described ingreater detail below. As shown in FIG. 5, the distal end of shield tube(160) simply includes a circular edge (166). As shown in FIG. 6, thedistal end of pusher tube (170) includes a distal face (176). In thepresent example, the difference between the inner diameter of pushertube (170) and the outer diameter of pusher tube (170) is greater thanthe difference between the inner diameter of shield tube (160) and theouter diameter of shield tube (160). Thus, distal face (176) presents amore prominent contact surface than circular edge (166). As shown inFIG. 7, the distal end of piercer (180) includes a sharp, multi-facetedpiercer tip (186) that is configured to pierce through a patient'stympanic membrane (TM). In the present example, piercer (180) alsoincludes a neck-down region (188) having a reduced diameter.

FIG. 8 shows the positioning of tubes (150, 160, 170), piercer (180),and PE tube (200) within cannula (120) before camshaft (130) startsrotating from a home position. As shown, piercer tip (186) of piercer(180) is positioned distal to leaves (156) of dilator tube (150), suchthat leaves (156) are positioned about neck-down region (188) of piercer(180). PE tube (200) is positioned within the distal end of shield tube(160), whose distal edge (166) is just proximal to leaves (156). Pushertube (170) is proximal to PE tube (200), with distal face (176) ofpusher tube (170) abutting the proximal end of PE tube (200). In thepresent example, PE tube (200) is resiliently biased to assume arivet-like shape presenting transverse petals (208) and a flange (206)(see FIG. 9). However, PE tube (200) is compressed against this bias,thereby assuming a generally cylindraceous configuration, when PE tube(200) is disposed within shield tube (160) as shown in FIG. 8.

FIG. 9 depicts a sequence of operation that occurs upon rotation ofcamshaft (130) from a home position to an actuated position, wheretracks (132, 134, 136, 138) are shown developed into a flat pattern forpurpose of illustration. The sequence starts at the top region of FIG.9, which shows the distal end of clear tip member (122) contacting thepatient's tympanic membrane (TM). At this stage, tubes (150, 160, 170),piercer (180), and PE tube (200) are at the positions shown in FIG. 8.Once camshaft (130) starts rotating at the urging of torsion spring(140), pins (154, 164, 174, 184) begin to ride along their respectivetracks (132, 134, 136, 138), such that piercer tip (186) and leaves(156) are driven distally through the patient's tympanic membrane (TM).While not directly shown in FIG. 8, it should be understood that tubes(160, 170, 190) are also driven distally during this transition, thoughtubes (160, 170, 190) remain proximal to clear tip member (122) at thisstage. As camshaft (130) continues to rotate, piercer (180) beginsretracting proximally while tubes (160, 170, 190) continue to advancedistally. As shown, shield tube (160) spreads leaves (156) outwardlyfrom their default positions. This further dilates the puncture site inthe tympanic membrane (TM). Shield tube (160) continues to contain PEtube (200) at this stage. As camshaft (130) continues to rotate, piercer(180) and dilator (150) retract proximally behind clear tip member(122). Shield tube (160) also begins to retract proximally, while pushertube (170) remains longitudinally stationary. This relative movementuncovers the distal end of PE tube (200), such that the resilient biasof petals (208) causes petals (208) to flex to transverse positions,thereby effectively forming a flange on the far side of the tympanicmembrane (TM). Piercer (180) eventually returns to the fully proximalposition, dilator (170) eventually returns to the fully proximalposition, and pusher tube (170) eventually reaches a fully distalposition. As camshaft (130) continues to rotate, shield tube (160)continues to retract proximally while pusher tube (170) remainslongitudinally stationary. This relative movement uncovers the proximalend of PE tube (200), such that the resilient bias of PE tube (200) isallowed to form flange (206) on the near side of the tympanic membrane(TM).

[Camshaft (130) stops rotating when the inwardly protruding boss ofhousing (104) engages plug (135) in stopper track (137). The elastomericnature of plug (135) provides a relatively soft stop, such that plug(135) acts as a damper. This may reduce jolting of PETDD (100) whencamshaft (130) comes to a stop and/or may prevent camshaft (130) frommaking a popping or snapping sound when camshaft (130) comes to a stop.Upon completion of the above described sequence shown in FIG. 9, cannula(120) is withdrawn from the patient's ear, leaving the actuated PE tube(200) in place in the patient's tympanic membrane (TM). Petals (208) andflange (206) cooperate to maintain the position of PE tube (200) in TM,while the passageway (204) formed by the interior of PE tube (200) (seeFIGS. 8 and 17-20) provides a path for fluid communication (e.g.,venting) between the patient's middle ear and outer ear. This fluid pathfurther provides pressure equalization between the patient's middle earand outer ear and/or promotes drainage of fluid from the middle ear viathe Eustachian tube.

As noted above, PETDD (100) of the present example includes a triggermechanism that is configured to selectively resist rotation of camshaft(130) by torsion spring (140). As best seen in FIGS. 10-16B, the triggermechanism of this example comprises a pawl member (190) that selectivelyengages pushbutton (106) and camshaft (130). Pawl member (190) includeslaterally extending pins (192) that couple pawl member (190) withhousing (104). While housing (104) prevents pawl member (190) frommoving laterally within housing (104), housing (104) permits pawl member(190) to pivot freely about pins (192) within housing (104). Pawl member(190) includes a distally facing boss rib (194) that extends vertically.Pawl member (190) also includes a pull-pin opening (196) and aproximally facing pawl ridge (198). Boss rib (194) is configured toselectively engage a proximally facing boss rib (107) of pushbutton(106) as will be described in greater detail below. Pull-pin opening(196) is configured to receive pull-pin (108), which assists to preventpawl member (190) from pivoting about pins (192) when pull-pin (108) isdisposed in pull-pin opening (196). Pawl ridge (198) includes chamferedlateral faces (199) and is configured to selectively engage a retentionfeature (131) of camshaft (130). In particular, when pawl member (190)is in a first position as shown in FIGS. 14, 15A, and 16A, pawl ridge(198) is engaged with retention feature (131) and prevents camshaft(130) from rotating despite the rotational bias provided by torsionspring (140). When pawl member (190) is pivoted to a second position asshown in FIGS. 15B and 16B, pawl ridge (198) disengages retentionfeature (131), enabling camshaft (130) to rotate under the influence oftorsion spring (140) to provide the sequence of operation describedabove.

As best seen in FIGS. 10 and 13, pushbutton (106) includes a pull-pinopening (109) that is configured to receive pull-pin (108). Pushbutton(106) is prevented from translating laterally relative to housing (104)when pull-pin (108) is disposed within pull-pin opening (109). Pull-pin(108) thus provides a lockout for pushbutton (106). To unlock pushbutton(106), pull-pin (108) may be pulled distally out of housing (104). Asnoted above, pushbutton (106) also includes a proximally facing boss rib(107) that extends vertically. When pushbutton (106) is laterallycentered within housing (104), boss rib (107) engages boss rib (194), asshown in FIGS. 15A and 16A. This engagement prevents pawl member (190)from pivoting distally about pins (192). Pushbutton (106) and pawlmember (190) together thus effectively lock camshaft (130) whenpushbutton (106) is laterally centered within housing (104).

When pushbutton (106) is laterally displaced relative to housing (104)(i.e., when a user depresses an exposed portion of pushbutton (106)laterally relative to housing (104)), bosses (107, 194) disengage suchthat pushbutton (106) no longer blocks pivoting of pawl member (190).Due to the torsional bias of camshaft (130), the ramped configuration ofretention feature (131), and the chamfered lateral faces (199) of pawlridge (198), camshaft (130) forces pawl member (190) to pivot out of theway to the position shown in FIGS. 15B and 16B when pushbutton (106) isno longer blocking pawl member (190). This enables camshaft (130) tocomplete the operational drive sequence described above. Whilepushbutton (106) is depicted as being pushed in one lateral direction,it should be understood that the same triggering operation may beprovided when pushbutton (106) is pushed in the opposite lateraldirection from the center position. With portions of pushbutton (106)being exposed through housing (104) on each side of handpiece (102),this allows the operator to select which side of pushbutton (106) topress.

It should be understood that the foregoing components, features, andoperabilities of PETDD (100) are merely illustrative examples. A PETDD(100) may include various other features in addition to or in lieu ofthose described above. By way of example only, any of the devices hereinmay also include one or more of the various features disclosed in any ofthe various references that are incorporated by reference herein. Someadditional merely illustrative variations of PETDD (100) will bedescribed in greater detail below, while other variations of PETDD (100)will be apparent to those of ordinary skill in the art in view of theteachings herein.

II. Exemplary Pressure Equalization Tube

FIGS. 17-20 show PE tube (200) in greater detail. PE tube (200) of thisexample includes a cylindraceous body (202) that defines a passageway(204). A flange (206) is located at the proximal end of body (202) whilea set of petals (208) are located at the distal end of body (202).Flange (206) includes a plurality of inwardly directed recesses (207).Recesses (207) are configured to facilitate flexing of flange (206) froman outwardly extended position to a generally cylindraceous positionwhere the material forming flange (206) extends longitudinally. Whilethree recesses (207) are shown, it should be understood that any othersuitable number of recesses (207) may be provided. Similarly, whilethree petals (208) are shown, it should be understood that any othersuitable number of petals (208) may be provided.

PE tube (200) is formed of a resilient material that is biased to assumethe rivet like configuration shown in FIGS. 17-20. However, flange (206)and petals (208) may be flexed inwardly toward the longitudinal axis ofbody (202) to provide PE tube (200) with a cylindraceous configuration.In particular, flange (206) and petals (208) may be flexed such thattheir outer surfaces are at the same radial distance from thelongitudinal axis as the outer perimeter of body (202). This radialdistance may be slightly less than the radial distance associated withthe inner diameter of shield tube (160), such that PE tube (200) maycollapse to fit within shield tube (160). When PE tube (200) is disposedin a tympanic membrane (TM), petals (208) are located medially (i.e., onthe middle ear side) while flange (206) is located laterally (i.e., onthe outer ear side). By way of example only, PE tube (200) may also beconfigured in accordance with at least some of the teachings of U.S.patent application Ser. No. 13/800,113, entitled “Tympanic MembranePressure Equalization Tube,” filed on Mar. 13, 2013, now U.S. Pat. No.9,011,363, issued Apr. 21, 2015, the disclosure of which is incorporatedby reference herein. Other suitable forms that PE tube (200) may takewill be apparent to those of ordinary skill in the art in view of theteachings herein.

III. Exemplary Pressure Equalization Tube Delivery Instrument Variations

Those of ordinary skill in the art will appreciate that the tympanicmembrane (TM) may extend along a plane that is oblique to the directionof insertion of PETDD (100). In other words, the plane of the tympanicmembrane (TM) may be obliquely angled relative to the longitudinal axisof cannula (120). By way of example only, the tympanic membrane (TM) maydefine an angle between approximately 79 degrees and approximately 54degrees with the longitudinal axis of cannula (120). This obliqueorientation of the tympanic membrane (TM) may pose difficulties withrespect to some versions of a PETDD (100) that has a flat tip. Forinstance, inadequate apposition between the distal edge of tip member(122) and the tympanic membrane (TM) may lead to unsuccessful deploymentof PE tube (200). This may prompt some operators of PETDD (100) to applysignificant pressure against the tympanic membrane (TM), to deform thetympanic membrane (TM) into a position of substantial apposition withthe flat-faced tip member (122) of PETDD (100). It may be desirable tomaximize the apposition between the distal edge of tip member (122) andthe tympanic membrane (TM), such as by enabling the distal edge of tipmember (122) to complement the orientation of the tympanic membrane (TM)as much as possible, without requiring an operator to apply significantpressure against the tympanic membrane (TM) in order to achieve adequateapposition. The following examples include merely illustrativevariations of PETDD (100) that may enhance apposition with the tympanicmembrane (TM).

A. Exemplary PETDD with Tip Sleeve Having Complementary Bevel

FIG. 21 depicts an exemplary variation of PETDD (100) having a beveledtip member (300) secured to the distal end of cannula (100). All of theother components in this variation are the same as those described abovefor PETDD (100). As can be seen, the distal edge (121) of cannula (120)extends along a plane that is perpendicular to the longitudinal axis ofcannula (120). Beveled tip member (300) is secured to the distal end ofcannula (120). Beveled tip member (300) includes an interior annularshoulder (304), such that cannula (120) is inserted into the proximalend of beveled tip member (300) until distal edge (121) of cannula (120)engages annular shoulder (304). An adhesive, interference fit, and/orany other suitable structure/technique may be used to secure beveled tipmember (300) to the distal end of cannula (120). Beveled tip member(300) and cannula (120) are both configured to be inserted through theear canal of the patient to reach the tympanic membrane (TM). In thepresent example, beveled tip member (300) is formed of a transparentmaterial, which may facilitate visualization with an endoscope or othervisualization apparatus. In versions where beveled tip member (300) istransparent, the distal edge (302) of beveled tip member (300) maynevertheless be opaque or colored, to assist in visualizing thepositioning of distal edge (302) against the tympanic membrane (TM).

Distal edge (302) of beveled tip member (300) is formed at an obliqueangle in the present example. By way of example only, distal edge (302)may extend along a plane that defines an angle between approximately 79degrees and approximately 54 degrees with the longitudinal axis ofcannula (120). In other words, distal edge (302) may be oriented at anangle between about 11 degrees and about 36 degrees relative to theplane along which distal edge (303) of cannula (120) extends.Alternatively, any other suitable angles may be used. In the presentexample, the orientation of distal edge (302) may substantiallycomplement the orientation of the tympanic membrane (TM). Accordingly,when beveled tip member (300) is positioned adjacent to the tympanicmembrane (TM) as shown in FIG. 21, distal edge (302) may achievesubstantial apposition with the tympanic membrane (TM) without theoperator of PETDD (300) having to apply significant pressure against thetympanic membrane (TM).

In an exemplary use, an operator may first anesthetize the patient's earusing an iontophoresis system as described in various references citedherein. Once the ear has been suitably anesthetized, the operator mayremove pull-pin (108) from handpiece (102) by pulling distally onpull-pin (108) until pull-pin (108) is fully separated from housing(104). This will effectively unlock pushbutton (106) and enableoperation of PETDD (100). The operator may then insert cannula (120)into a patient's ear canal. With the aid of a visualization system suchas a scope, the operator may position distal edge (302) of beveled tipmember (300) against the tympanic membrane (TM). This may require theoperator to rotate PETDD (100) about the longitudinal axis of cannula(120) in order to orient distal edge (302) parallel with the tympanicmembrane (TM). In some versions of PETDD (100), cannula (120) isrotatable relative to handpiece (102), such that the user may readilyrotate cannula (120) about the longitudinal axis of cannula (120) whileholding handpiece (120) stationary.

Once distal edge (302) has been oriented to be substantially parallelwith the tympanic membrane (TM), and distal edge (302) is in appositionwith the tympanic membrane (TM), the operator may press pushbutton (106)laterally to fire PETDD (100) and thereby deploy a PE tube (200) in thetympanic membrane (TM). It should be understood that the complementaryorientations of distal edge (302) and the tympanic membrane (TM) mayreduce the chances that PE tube (200) might fail to properly enter thedilated incision in the tympanic membrane (TM) during deployment. OncePE tube (200) is positioned within the tympanic membrane (TM), PETDD(100) may be retracted proximally and PE tube (200) may remain in thetympanic membrane (TM) in the rivet-like configuration shown in FIGS.17-20.

B. Exemplary PETDD with Tip Having Opposing Bevel

FIGS. 22A-22B depict an exemplary variation of PETDD (100) having acannula (400) with a beveled distal edge (402). All of the othercomponents in this variation are the same as those described above forPETDD (100). As can be seen, the distal edge (402) of cannula (400)extends along a plane that defines an angle between approximately 79degrees and approximately 54 degrees with the longitudinal axis ofcannula (400). Alternatively, any other suitable angles may be used.

In an exemplary use, an operator may first anesthetize the patient's earusing an iontophoresis system as described in various references citedherein. Once the ear has been suitably anesthetized, the operator mayremove pull-pin (108) from handpiece (102) by pulling distally onpull-pin (108) until pull-pin (108) is fully separated from housing(104). This will effectively unlock pushbutton (106) and enableoperation of PETDD (100). The operator may then insert cannula (400)into a patient's ear canal. With the aid of a visualization system suchas a scope, the operator may position the distal-most portion (404) ofdistal edge (402) adjacent the tympanic membrane (TM). However, insteadof placing distal edge (402) in apposition with the tympanic membrane(TM), PETDD (100) is oriented such that distal edge (402) forms avertically opposing angle with the tympanic membrane (TM). Inparticular, distal edge (402) forms an angle with a vertical axis (VA)that is approximately the same as the angle formed between the tympanicmembrane (TM) and the vertical axis (VA), with those angles beinglocated on opposite sides of the vertical axis (VA). By way of exampleonly, these angles may be between approximately 11 degrees andapproximately 36 degrees. In some instances, the user may rotate PETDD(100) about the longitudinal axis of cannula (400) in order to achievethis positioning. In some versions of PETDD (100), cannula (400) isrotatable relative to handpiece (102), such that the user may readilyrotate cannula (400) about the longitudinal axis of cannula (400) whileholding handpiece (120) stationary.

Once PETDD (100) is oriented such that distal edge (402) forms avertically opposing angle with the tympanic membrane (TM), the operatormay press pushbutton (106) laterally to fire PETDD (100) and therebydeploy a PE tube (200) in the tympanic membrane (TM). It should beunderstood that the angularly opposing orientations of distal edge (402)and the tympanic membrane (TM) may promote PE tube (200) pivoting intothe position shown in FIG. 22B as PE tube (200) is being deployed intothe tympanic membrane (TM). This pivoting of PE tube (200) may reducethe risk of PE tube (200) being undesirably displaced laterally ormedially during deployment of PE tube (406). As can also be seen in FIG.22B, a portion of pusher tube (170) may protrude slightly from the opendistal end of cannula (120) during deployment of PE tube (200). (Otherfeatures inside cannula (120) are omitted from the view in FIG. 22B forclarity). Once PE tube (200) is positioned within the tympanic membrane(TM), PETDD (100) may be retracted proximally and PE tube (200) mayremain in the tympanic membrane (TM) in the rivet-like configurationshown in FIGS. 17-20. It should be understood that the deploymenttechnique shown in FIGS. 22A-22B may also be performed with a PETDD(100) that has a beveled tip member (300) like the one shown in FIG. 21,simply by rotating cannula (120) about its longitudinal axis byapproximately 180 degrees.

C. Exemplary PETDD with Driven Apposition Enhancement Features

FIG. 23 depicts another exemplary variation of PETDD (100) having a tipmember (500) that includes a sensor (502). All of the other componentsin this variation are the same as those described above for PETDD (100).It should be understood that tip member (500) may have a substantiallyflat distal end as shown in FIG. 23, a beveled distal end like beveledtip member (300) shown in FIG. 21, or any other suitable configuration.In the present example, sensor (502) is in communication with acontroller (510). Sensor (502) may communicate with controller (510) viaone or more wires, one or more traces formed in or applied to cannula(120), wireless communication means, etc.

Controller (510) is in communication with a feedback device (512), avacuum source (514), and a memory (516). Controller (510) is operable toselectively activate vacuum source (514) and/or feedback device (512)based on data from sensor (502) and memory (516) and/or in response tooperator input. Controller (510) may comprise a microprocessor, ASIC,and/or various other components. Examples of components that may beincorporated into controller (510) will be described in greater detailbelow. In addition, other suitable components that may be incorporatedinto controller (510) will be apparent to those of ordinary skill in theart in view of the teachings herein. It should also be understood thatone or more of the foregoing features may be omitted from PETDD (100) ifdesired. By way of example only, some other versions of PETDD (100) maylack sensor (502), feedback device (512), and memory (516). As anothermerely illustrative example, some other versions of PETDD (100) may lackvacuum source (514). Other suitable combinations and variations will beapparent to those of ordinary skill in the art in view of the teachingsherein.

Vacuum source (514) is further coupled with cannula (120) and tip member(500), such that vacuum source (514) is operable to provide suction totip member (500) based on instructions from controller (510). In someversions, this suction is used to assist in drawing the tympanicmembrane (TM) against tip member (500), thereby promoting appositionbetween the tympanic membrane (TM) and tip member (500). In some uses ofPETDD (100), an operator may wish to have vacuum source (514)deactivated during insertion of cannula (102) through the patient's earcanal; then activate vacuum source (514) via controller (510) after tipmember (500) reaches the patient's tympanic membrane (TM). In drawingthe tympanic membrane (TM) against tip member (500), the suction fromvacuum source (514) may close any gaps that might otherwise remain fromthe operator's manual positioning of tip member (500).

In addition to or as an alternative to promoting apposition between tipmember (500) and the tympanic membrane (TM), vacuum may be used toassist with sensing apposition between the tympanic membrane (TM) andtip member (500). For instance, sensor (502) may be operable to sense aphysical parameter associated with fluid pressure in cannula (120) andtip member (500). With vacuum source (514) drawing suction as cannula(120) and tip member (500) are advanced toward the tympanic membrane(TM), the fluid pressure may remain substantially constant. However, assoon as tip member (500) achieves substantial apposition with thetympanic membrane (TM), the fluid pressure may suddenly andsubstantially drop. This pressure drop may be detected through sensor(502) and processed by controller (510). Various suitable forms thatsensor (502) may take will be apparent to those of ordinary skill in theart in view of the teachings herein.

Controller (510) may monitor data from sensor (502) and compare itagainst one or more predetermined values stored in memory (516). Whenthat data exceeds a threshold, falls below a threshold, or meets someother predetermined condition(s), controller (510) may trigger apredetermined response based on control logic/algorithms stored inmemory (516). By way of example only, controller (510) may automaticallydeactivate vacuum source (514) in response to data from sensor (502).Such deactivation may occur upon the fluid pressure in cannula (120)dropping below a certain threshold. Alternatively, such deactivation mayoccur upon lapse of a certain time period following the fluid pressureof cannula (120) dropping below a certain threshold. As yet anothermerely illustrative example, controller (510) may automaticallydeactivate vacuum source (514) in response to deployment of PE tube(200). Of course, vacuum source (514) may simply be deactivated inresponse to user input directly from the operator of PETDD (100).

In some instances, controller (510) may activate feedback device (512)in response to data from sensor (502) exceeding a threshold, fallingbelow a threshold, or satisfying some other predetermined condition(s).Feedback device (512) may provide any suitable perceivable feedback(e.g., audio, visual, and/or haptic feedback) to the operator of PETDD(100), to indicate to the operator that a significant event hasoccurred. For example, feedback device (512) may be used to inform theoperator that the fluid pressure within cannula (120) has dropped belowa threshold, thereby indicating to the operator that tip member (500)has achieved sufficient apposition with the tympanic membrane (TM). Inaddition or in the alternative, feedback device (512) may be used toinform the operator that PE tube (200) has been deployed. Other suitableevents that may be alerted to the user through feedback device (512)will be apparent to those of ordinary skill in the art in view of theteachings herein. Similarly, various suitable forms that feedback device(512) may take will be apparent to those of ordinary skill in the art inview of the teachings herein.

In the example above, sensor (502) comprises a pressure sensor that isoperable to detect fluid pressure within cannula (120). In addition orin the alternative, sensor (502) may be operable to detect strain incannula (120) or tip member (500); and/or otherwise detect appositionbetween tip member (500) and the tympanic membrane (TM). By way ofexample only, sensor (502) may comprise a force sensor such as a straingauge, inductive sensor, piezoelectric sensor and/or any other suitabletype of sensor. Additional merely exemplary forms that sensor (502) maytake are described in greater detail below. In the present example,sensor (502) is positioned near the distal end of tip member (500), suchthat sensor (502) may detect slight deformations that may occur in tipmember (500) upon reaching sufficient apposition with the tympanicmembrane (TM). It will be appreciated that sensor (502) may instead bepositioned at any other suitable location along cannula (120). By way ofexample only, sensor (502) may be positioned at the interface of cannula(120) and tip member (500).

In versions where sensor (502) is operable to detect strain in cannula(120), controller (510) and feedback device (512) may be configured toprovide the operator with real-time feedback associated with strain incannula (120). This feedback may be interpreted by the user to indicatewhether the operator should push harder distally on cannula (120). Forinstance, before tip member (500) reaches the tympanic membrane (TM),controller (510) may drive feedback device (512) to indicate to theoperator that the operator needs to continue pushing distally on cannula(120). Once tip member (500) contacts the tympanic membrane (TM), sensor(502) may detect such contact; and controller (510) may responsivelydrive feedback device (512) to indicate to the operator that theoperator has reached the tympanic membrane (TM). Feedback device (512)may further indicate to the operator that the operator needs to applymore or less force distally on cannula (120) in order to achieve properapposition. Similarly, feedback device (512) may alert the operator whenthe distal force being applied to the tympanic membrane (TM) isexcessive, thereby preventing potential damage to the tympanic membrane(TM). Other suitable ways in which sensor (502) and feedback device(512) may be used will be apparent to those of ordinary skill in the artin view of the teachings herein.

It should also be understood that two or more sensors (502) may be usedin tip member (500), in cannula (120), and/or elsewhere. In versionswith two or more sensors (502), such sensors (502) may detect the samekind of parameter (e.g., two sensors (502) detecting fluid pressure)and/or different parameters (e.g., one sensor (502) detecting fluidpressure and another sensor (502) detecting strain in tip member (500)).The control algorithms for controller (510) may be responsive to variouspermutations of data collected through a plurality of sensors (502).Various combinations of sensors (502) and types of control algorithmsthat may be based on data from two or more sensors (502) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

IV. Exemplary Apposition Sensing Features for Pressure Equalization TubeDelivery Instrument

As noted above, a combination of a controller (510) and sensor (502) maybe used to determine whether a suitable degree of apposition has beenachieved between tip member (122, 500) and a tympanic membrane (TM).Controller (510) may process data from sensor (502) to drive a feedbackdevice (512) to enable the operator to evaluate whether a suitabledegree of apposition has been achieved between tip member (122, 500) anda tympanic membrane (TM). Information from feedback (512) may serve as asupplement or substitute for tactile feedback provided to the operatorthrough PETDD (100) itself. The examples below include various formsthat sensor (502) and controller (510) may take, in addition to or as analternative to the forms described above. It should therefore beunderstood that the teachings below may be readily combined with theteachings above in various permutations. For instance, while severalexamples described below include feedback device (512) but not vacuumsource (514), a vacuum source (514) may of course be readilyincorporated into the below examples if desired. Still other suitablecombinations and variations will be apparent to those of ordinary skillin the art in view of the teachings herein.

A. Exemplary Apposition Sensing with Resistance through AnnularElectrode

FIG. 24 shows a variation of PETDD (100) having a tip member (650) thatincludes a distally facing annular electrode (652). Tip member (650) isformed of an electrically insulative material (e.g., plastic, etc.),such that electrode (652) is the only exposed conductive portion. Insome versions, electrode (652) is formed as an annular trace in thedistal edge of tip member (650). A controller (610) is in communicationwith electrode (652) and applies a voltage to electrode (652). By way ofexample only, a wire, trace, and/or other feature(s) may couplecontroller (610) with electrode (652). Controller (610) is also incommunication with electrical ground (G), a ground pad (630), andfeedback device (512). Ground pad (630) comprises a conventional groundpad that may be applied to an exposed portion of the patient's skin.Ground pad (630) thus provides a ground return path with the patientwhen electrode (652) contacts the patient while in an activated state.

Controller (610) also includes an ohmmeter (620). Ohmmeter (620) isplaced in line between electrode (652) and both ground pad (630) andground (G); such that ohmmeter (620) is configured to detect resistance(if direct current is used) or impedance (if alternating current isused) between electrode (652) and ground pad (630). The resistance orimpedance detected through ohmmeter (620) may vary based on the degreeof contact between electrode (652) and the patient. For instance, whenconductive electrode (652) is not contacting the patient at all,ohmmeter (620) may register an infinite level of resistance/impedance,indicating an open circuit. When electrode (652) comes into physicalcontact with the tympanic membrane (TM), the resistance/impedancebetween electrode (652) and ground pad (630) is substantially reduced.The reduction in resistance/impedance may drop in accordance with thedegree to which electrode (652) (and, hence, tip member (650)) contactsthe tympanic membrane (TM). For instance, when electrode (652) (and,hence, tip member (650)) only partially contacts the tympanic membrane(TM), the resistance/impedance registered by ohmmeter (620) may dropslightly; but when electrode (652) (and, hence, tip member (650)) fullycontacts the tympanic membrane (TM), the resistance/impedance registeredby ohmmeter (620) may drop significantly. The resistance/impedance valueregistered by ohmmeter (620) may thus be inversely proportional to thedegree of apposition between electrode (652) (and, hence, tip member(650)) and the tympanic membrane (TM), with high resistance/impedancevalues being associated with low apposition percentages and lowresistance/impedance values being associated with high appositionpercentages.

In some instances, feedback device (512) provides a real-time numericalvalue associated with sensed resistance/impedance, and the operator maydetermine when sufficient apposition has been achieved based on theirreading of feedback device (512). In addition or in the alternative,feedback device (512) may comprise a set of LEDs that illuminate redwhen electrode (652)/tip member (650) is not contacting the tympanicmembrane (TM), that illuminate yellow when electrode (652)/tip member(650) initially contacts the tympanic membrane (TM) but without anadequate degree of apposition, and that illuminate green when electrode(652)/tip member (650) achieves adequate apposition with the tympanicmembrane (TM). Other suitable forms that feedback device (512) may taketo provide visual feedback will be apparent to those of ordinary skillin the art in view of the teachings herein.

As another merely illustrative example, feedback device (512) mayprovide audible feedback to the operator. For instance, feedback device(512) may emit a buzz or an audible tone as soon as electrode (652)/tipmember (650) achieves adequate apposition with the tympanic membrane(TM). As yet another merely illustrative example, feedback device (512)may start emitting a pattern of tones or beeps as soon as electrode(652)/tip member (650) initially contacts the tympanic membrane (TM) butwithout an adequate degree of apposition, with the pattern of tonesincreasing in frequency and/or volume as the degree of appositionincreases. Other suitable forms that feedback device (512) may take toprovide audible feedback will be apparent to those of ordinary skill inthe art in view of the teachings herein. In addition to or as analternative to audible and/or visual feedback, feedback device (512) mayprovide tactile feedback such as vibrations, etc. In some instances,PETDD (100) may be operable to automatically insert PE tube (200) intothe tympanic membrane (TM) upon detection of sufficient apposition.Regardless of the form of feedback, suitable levels ofresistance/impedance that may be set to trigger feedback device (512)will be apparent to those of ordinary skill in the art in view of theteachings herein.

B. Exemplary Apposition Sensing with Resistance Through DiscreteElectrodes

FIG. 25 shows a variation of PETDD (100) having a tip member (750) thatincludes a plurality of distally facing discrete electrodes (752 a, 752b, 752 c, 752 d, 752 e, 752 f). Electrodes (752 a, 752 b, 752 c, 752 d,752 e, 752 f) are arranged in an annular array. While six electrodes(752 a, 752 b, 752 c, 752 d, 752 e, 752 f) are shown, it should beunderstood that any other suitable number may be used in any othersuitable arrangement. Electrodes (752 a, 752 b, 752 c, 752 d, 752 e, 752f) are isolated from each other in this example. Tip member (750) isformed of an electrically insulative material (e.g., plastic, etc.),such that electrodes (752 a, 752 b, 752 c, 752 d, 752 e, 752 f) are theonly exposed conductive portions. In some versions, each electrode (752a, 752 b, 752 c, 752 d, 752 e, 752 f) is formed as a discrete trace inthe distal edge of tip member (750). In some other versions eachelectrode (752 a, 752 b, 752 c, 752 d, 752 e, 752 f) is formed byexposing a portion of wire wrapped over the distal edge of tip member(750). Other suitable ways in which electrodes (752 a, 752 b, 752 c, 752d, 752 e, 752 f) may be formed will be apparent to those of ordinaryskill in the art in view of the teachings herein.

A controller (710) is in communication with electrodes (752 a, 752 b,752 c, 752 d, 752 e, 752 f) and applies a voltage to each electrode (752a, 752 b, 752 c, 752 d, 752 e, 752 f). By way of example only, wires,traces, and/or other feature(s) may couple controller (710) withelectrodes (752 a, 752 b, 752 c, 752 d, 752 e, 752 f). Controller (710)is also in communication with electrical ground (G), a ground pad (630),and feedback device (512). Ground pad (630) comprises a conventionalground pad that may be applied to an exposed portion of the patient'sskin. Ground pad (630) thus provides a ground return path with thepatient when any electrode (752 a, 752 b, 752 c, 752 d, 752 e, 752 f)contacts the patient while in an activated state.

Controller (710) also includes a plurality of ohmmeters (720 a, 720 b,720 c, 720 d, 720 e, 7200. Each ohmmeter (720 a, 720 b, 720 c, 720 d,720 e, 7200 is placed in line between a corresponding electrode (752 a,752 b, 752 c, 752 d, 752 e, 7520 and both ground pad (630) and ground(G); such that each ohmmeter (720 a, 720 b, 720 c, 720 d, 720 e, 7200 isconfigured to detect resistance (if direct current is used) or impedance(if alternating current is used) between a particular correspondingelectrode (752 a, 752 b, 752 c, 752 d, 752 e, 7520 and ground pad (630).The resistance or impedance detected through each ohmmeter (720 a, 720b, 720 c, 720 d, 720 e, 7200 may vary based on the degree of contactbetween the corresponding electrode (752 a, 752 b, 752 c, 752 d, 752 e,7520 and the patient. For instance, when a given electrode (752 a, 752b, 752 c, 752 d, 752 e, 7520 is not contacting the patient at all, thecorresponding ohmmeter (720 a, 720 b, 720 c, 720 d, 720 e, 720 f) mayregister an infinite level of resistance/impedance, indicating an opencircuit. When the same electrode (752 a, 752 b, 752 c, 752 d, 752 e,7520 comes into physical contact with the tympanic membrane (TM), theresistance/impedance between that electrode (752 a, 752 b, 752 c, 752 d,752 e, 752 f) and ground pad (630) is substantially reduced.

Controller (710) may determine the degree of apposition based on thenumber of electrodes (752 a, 752 b, 752 c, 752 d, 752 e, 752 f) showinga substantial reduction in resistance/impedance, as measured throughohmmeters (720 a, 720 b, 720 c, 720 d, 720 e, 720 f). For instance,controller (710) may activate feedback device (512) based on the numberof electrodes (752 a, 752 b, 752 c, 752 d, 752 e, 752 f) showing asubstantial reduction in resistance/impedance. In some such versions,the triggering threshold may thus be the number of electrodes (752 a,752 b, 752 c, 752 d, 752 e, 752 f) contacting the tympanic membrane(TM); rather than a particular resistance/impedance value alone servingas a triggering threshold. Of course, feedback device (512) in thiscontext may be configured and operable in accordance with any of theteachings herein relating to feedback device (512).

FIG. 26 shows another variation of PETDD (100) having a tip member (850)that includes a plurality of distally facing discrete electrodes (852 a,852 b, 852 c, 852 d, 852 e, 852 f). Electrodes (852 a, 852 b, 852 c, 852d, 852 e, 852 f) are arranged in an annular array. While six electrodes(852 a, 852 b, 852 c, 852 d, 852 e, 852 f) are shown, it should beunderstood that any other suitable number may be used in any othersuitable arrangement. Electrodes (852 a, 852 b, 852 c, 852 d, 852 e, 852f) form pairs in this example. In particular, electrodes (852 a 852 d)form a pair, electrodes (852 b, 852 e) form a pair, and electrodes (852c, 852 f) form a pair. The electrodes (852 a, 852 b, 852 c, 852 d, 852e, 852 f) of each pair are located in diametrically opposing positionsalong the outer perimeter of the distal face of tip member (850). Tipmember (850) is formed of an electrically insulative material (e.g.,plastic, etc.), such that electrodes (852 a, 852 b, 852 c, 852 d, 852 e,852 f) are the only exposed conductive portions. In some versions, eachelectrode (852 a, 852 b, 852 c, 852 d, 852 e, 852 f) is formed as adiscrete trace in the distal edge of tip member (850). In some otherversions each electrode (852 a, 852 b, 852 c, 852 d, 852 e, 852 f) isformed by exposing a portion of wire wrapped over the distal edge of tipmember (850). Other suitable ways in which electrodes (852 a, 852 b, 852c, 852 d, 852 e, 852 f) may be formed will be apparent to those ofordinary skill in the art in view of the teachings herein.

A controller (810) is in communication with electrodes (852 a, 852 b,852 c, 852 d, 852 e, 8520 and applies a voltage to each pair ofelectrodes (852 a, 852 b, 852 c, 852 d, 852 e, 8520. By way of exampleonly, wires, traces, and/or other feature(s) may couple controller (810)with electrodes (852 a, 852 b, 852 c, 852 d, 852 e, 8520. Controller(810) is also in communication with feedback device (512). Controller(810) also includes a plurality of ohmmeters (820 a, 820 b, 820 c). Eachohmmeter (820 a, 820 b, 820 c) is associated with a particular pair ofelectrodes (852 a, 852 b, 852 c, 852 d, 852 e, 8520. In particular,ohmmeter (820 a) is coupled with electrodes (852 c, 8520, ohmmeter (820b) is coupled with electrodes (852 a, 8520, and ohmmeter (820 c) iscoupled with electrodes (852 b, 852 e). Each ohmmeter (820, 820 b, 820c) is configured to detect resistance (if direct current is used) orimpedance (if alternating current is used) between the electrodes (852a, 852 b, 852 c, 852 d, 852 e, 8520 of the pair associated with ohmmeter(820 a, 820 b, 820 c). Thus, ohmmeter (820 a) is configured to detectresistance/impedance between electrodes (852 c, 8520, ohmmeter (820 b)is configured to detect resistance/impedance between electrodes (852 a,8520, and ohmmeter (820 c) is configured to detect resistance/impedancebetween electrodes (852 b, 852 e). The resistance or impedance detectedthrough each ohmmeter (820 a, 820 b, 820 c) may vary based on the degreeof contact between the corresponding electrodes (852 a, 852 b, 852 c,852 d, 852 e, 8520 and the patient. For instance, when a given electrode(852 a, 852 b, 852 c, 852 d, 852 e, 8520 pair is not contacting thepatient at all, the corresponding ohmmeter (820 a, 820 b, 820 c) mayregister an infinite level of resistance/impedance, indicating an opencircuit. When the same electrode (852 a, 852 b, 852 c, 852 d, 852 e,8520 pair comes into physical contact with the tympanic membrane (TM),the resistance/impedance between the electrodes (852 a, 852 b, 852 c,852 d, 852 e, 8520 of that pair is substantially reduced.

Controller (810) may determine the degree of apposition based on thenumber of electrode (852 a, 852 b, 852 c, 852 d, 852 e, 8520 pairsshowing a substantial reduction in resistance/impedance, as measuredthrough ohmmeters (820 a, 820 b, 820 c). For instance, controller (810)may activate feedback device (512) based on the number of electrode (852a, 852 b, 852 c, 852 d, 852 e, 8520 pairs showing a substantialreduction in resistance/impedance. In some such versions, the triggeringthreshold may thus be the number of electrode (852 a, 852 b, 852 c, 852d, 852 e, 8520 pairs contacting the tympanic membrane (TM); rather thana particular resistance/impedance value alone serving as a triggeringthreshold. Of course, feedback device (512) in this context may beconfigured and operable in accordance with any of the teachings hereinrelating to feedback device (512). It should also be understood thatcontroller may monitor inductance of electrode (852 a, 852 b, 852 c, 852d, 852 e, 8520 pairs in addition to or in lieu of monitoringresistance/impedance.

C. Exemplary Apposition Sensing with Capacitance Through AnnularElectrode

FIG. 27 shows another variation of PETDD (100) having a tip member (950)that includes a distally facing annular electrode (952). Tip member(950) is formed of an electrically insulative material (e.g., plastic,etc.), such that electrode (952) is the only exposed conductive portion.In some versions, electrode (952) is formed as an annular trace in thedistal edge of tip member (950). Tip member (950) may also include anannular ridge protruding about the outer perimeter of electrode (952),which may act as a shield to prevent tissue that is positioned laterallyrelative to electrode (952) from affecting capacitance measurements asdescribed below. As another merely illustrative variation, as shown, forexample, FIG. 30, electrode (952) may be formed by a rod or otherfeature located somewhere within the inner diameter (951) of tip member(950).

A controller (910) is in communication with electrode (952) and appliesa voltage to electrode (952). By way of example only, a wire, trace,and/or other feature(s) may couple controller (910) with electrode(952). Controller (910) is also in communication with a ground pad(630), and feedback device (512). Ground pad (630) comprises aconventional ground pad that may be applied to an exposed portion of thepatient's skin. Ground pad (630) thus provides a ground return path withthe patient when electrode (952) contacts the patient while in anactivated state.

Controller (910) also includes a capacitance meter (920) and a capacitor(922). It should be understood that capacitor (922) is merely optional.Capacitance meter (920) is configured to detect the capacitance formedbetween electrode (952) and the tympanic membrane (TM). The capacitancedetected through capacitance meter (920) may thus vary based on thedegree of contact between electrode (952) and the patient. For instance,the capacitance formed between electrode (952) and the tympanic membrane(TM) may drop significantly as electrode (952) (and, hence, tip member(950)) comes into contact with the tympanic membrane (TM). In responseto this drop in capacitance, controller (910) may activate feedbackdevice (512) in accordance with any of the teachings herein relating tofeedback device (512).

D. Exemplary Apposition Sensing with Light Pipes

FIG. 28 shows a variation of PETDD (100) where a series of light pipes(1052) extend along cannula (120) and through a tip member (1050). Lightpipes (1052) distally terminate at distal ends (1054) located at thedistal edge of tip member (1050). Light pipes (1052) are opticallycoupled with light source (1060) and are operable to convey light fromlight source (1060) to distal ends (1054). By way of example only, lightpipes (1052) may be coupled with light source (1060) via optical fibersand/or any other suitable type of structures. While four light pipes(1052) are shown, it should be understood that any other suitable numberof light pipes (1052) may be provided. Light pipes (1052) are angularlyarrayed equidistantly about the perimeter of the distal edge of tipmember (1050) in this example, though it should be understood that anyother suitable arrangement may be used.

In some versions, light conveyed through light pipes (1052) isexternally visible along at least part of the length of light pipes(1052). For instance, a visible light may be seen through portion oflight pipes (1052) extending through tip member (1050). In some suchversions, the distal portions of light pipes (1052) are formed bychannels within tip member (1050). In the present example, light pipes(1052) emit visible light through distal ends (1054). This visible lightmay be transmitted to the tympanic membrane (TM) as the operator insertscannula (120) through the patient's ear canal. The light may appear asfour dots on the tympanic membrane (TM). As tip member (1050) engagesthe tympanic membrane (TM), these projected dots may eventually darken.Thus, the operator may receive visual feedback indicating the degree ofapposition between tip member (1050) and the tympanic membrane (TM),based on the degree to which light from light pipes (1052) has beendarkened by contact with the tympanic membrane (TM). Other suitable waysin which light pipes (1052) may be incorporated into PETDD (100) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

E. Exemplary Apposition Sensing Through Enhanced Visualization

FIG. 29 shows a variation of PETDD (100) where a light fiber (1100) andan imaging device (1200) extend through cannula (120) to tip member(122). Light fiber (1100) and imaging device (1200) terminate justproximal to the distal edge of tip member (122). Light fiber (1110) iscoupled with a light source (1102). Light fiber (1100) may be coupledwith light source (1102) using any suitable type of structures. Whilejust one light fiber (1100) is shown, it should be understood that anyother suitable number of light fibers (1100) may be provided. Lightfiber (1100) is positioned and operable to illuminate the tympanicmembrane (TM) right at the tympanostomy site. It should be understoodthat light fiber (1100) may even illuminate the tympanostomy site whentip member (122) is in full apposition with the tympanic membrane (TM).

Imaging device (1200) may comprise any suitable type of scope, imagingfiber, etc. that is operable to capture and transmit images. Varioussuitable forms that imaging device (1200) may take will be apparent tothose of ordinary skill in the art in view of the teachings herein.Imaging device (1200) is in communication with a display device (1202).Display device (1202) may comprise a video display screen, a set ofwearable loupes, and/or any other suitable device. Various suitableforms that display device (1200) may take, as well as various suitableways in which imaging device (1200) may be coupled with display device(1202), will be apparent to those of ordinary skill in the art in viewof the teachings herein. Imaging device (1200) is positioned andoperable to capture real-time video images of the tympanostomy site ascannula (120) is being inserted down the patient's ear canal. It shouldbe understood that imaging device (1200) may even capture video imagesof the tympanostomy site when tip member (122) is in full appositionwith the tympanic membrane (TM). Thus, with the combination of lightprojected from light fiber (1100) and video provided by imaging device(1200) and display device (1202), an operator may receive helpfulreal-time visual feedback indicating the positioning of tip member (122)and degree of apposition between tip member (122) and the tympanicmembrane. Due to the positioning of imaging device (1200) in thisexample, this visual feedback may be more useful than visual feedbackthat might otherwise be provided through an imaging device that ispositioned external to cannula (120).

V. Miscellaneous

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

The invention claimed is:
 1. An apparatus comprising: (a) a shaftassembly having a distal end having an annular distal face, wherein theshaft assembly comprises: (i) a cannula, and (ii) a pusher operable totranslate relative to the cannula; (b) a pressure equalization tubepositioned within the shaft assembly, wherein the pusher is operable todrive the pressure equalization tube out of the shaft assembly; and (c)at least one exposed electrode positioned at the distal end of the shaftassembly, wherein the at least one exposed electrode is (i) operable todetect a physical parameter associated with the distal end of the shaftassembly as the distal end of the shaft assembly is advanced toward andinto engagement with a tympanic membrane and (ii) comprises an annularelectrode disposed on the annular distal face of the distal end of theshaft assembly.
 2. The apparatus of claim 1, further comprising acontroller in communication with the at least one exposed electrode. 3.The apparatus of claim 2, further comprising a ground pad, wherein thecontroller is operable to detect electrical resistance or impedancebetween the at least one exposed electrode and the ground pad.
 4. Theapparatus of claim 2, wherein the controller is operable to detect acapacitance associated with the at least one exposed electrode.
 5. Theapparatus of claim 4, wherein the controller is operable to control afeedback device based on the capacitance associated with the at leastone exposed electrode, the feedback device operable to indicate when thedistal end of the shaft assembly engages with the tympanic membrane. 6.The apparatus of claim 2, wherein the controller includes a capacitancemeter, the capacitance meter configured to detect the capacitancebetween the at least one exposed electrode and the tympanic membrane. 7.The apparatus of claim 2, wherein the controller includes a capacitor.8. The apparatus of claim 1, further comprising a user feedback feature,wherein the user feedback feature is operable to alert an operator toone or more conditions associated with engagement between the distal endof the shaft assembly and the tympanic membrane based on informationfrom a sensor.
 9. The apparatus of claim 1, further comprising a vacuumsource operable to draw a tympanic membrane against the distal end ofthe shaft assembly.
 10. The apparatus of claim 9, wherein the pusherdefines a lumen, wherein the vacuum source is operable to communicatesuction through the lumen of the pusher.
 11. The apparatus of claim 9,further comprising a controller, wherein the controller is incommunication with the at least one exposed electrode, wherein thecontroller is in further communication with the vacuum source, whereinthe controller is configured to deactivate the vacuum source based atleast in part on information from a sensor indicating one or moreconditions associated with engagement between the distal end of theshaft assembly and a tympanic membrane.
 12. The apparatus of claim 1,wherein the distal end of the shaft assembly is beveled.
 13. Theapparatus of claim 1, further comprising an imaging device disposedwithin the shaft assembly.
 14. The apparatus of claim 1, wherein thedistal end of the shaft assembly includes an annular ridge formed of anelectrically insulative material, the annular ridge protruding about theouter perimeter of the annular electrode.
 15. An apparatus comprising:(a) a shaft assembly having a distal end having an annular distal face,wherein the shaft assembly comprises: (i) a cannula, and (ii) a pusheroperable to translate relative to the cannula; (b) a pressureequalization tube positioned within the shaft assembly, wherein thepusher is operable to drive the pressure equalization tube out of theshaft assembly; (c) at least one exposed electrode comprising an annularelectrode disposed on the annular distal face of the distal end of theshaft assembly; and (d) a controller, the controller operable to apply avoltage to the at least one exposed electrode such that the controllercan detect a capacitance formed between the at least one electrode and atympanic membrane.
 16. The apparatus of claim 15, further comprising auser feedback device operable to alert an operator of a change in thecapacitance formed between the at least one exposed electrode and thetympanic membrane.
 17. A method comprising: (a) disposing a shaftassembly proximate a tympanic membrane of a patient such that acapacitance is formed by a distal end of the shaft assembly and thetympanic membrane, the distal end having an annular distal face, theshaft assembly comprising: (i) a cannula, (ii) a pusher operable totranslate relative to the cannula, and (iii) at least one exposedelectrode including an annular electrode disposed on the annular distalface of the distal end of the shaft assembly; (b) advancing the shaftassembly into engagement with the tympanic membrane of the patient; (c)detecting a change in the capacitance formed by the distal end of theshaft assembly and the tympanic membrane; and (d) operating, in responseto the detecting, the pusher of the shaft assembly to drive a pressureequalization tube positioned within the shaft assembly out of the shaftassembly.
 18. An apparatus comprising: (a) a shaft assembly having adistal end, wherein the shaft assembly comprises: (i) a cannula, and(ii) a pusher operable to translate relative to the cannula; (b) apressure equalization tube positioned within the shaft assembly, whereinthe pusher is operable to drive the pressure equalization tube out ofthe shaft assembly; and (c) at least one exposed electrode positioned atthe distal end of the shaft assembly, wherein the at least one exposedelectrode is (i) operable to detect a physical parameter associated withthe distal end of the shaft assembly as the distal end of the shaftassembly is advanced toward and into engagement with a tympanic membraneand (ii) disposed within an inner diameter of the distal end of theshaft assembly.